Ball mill drum



y 1969 J. 5. ECKERT ET AL 3,454,233

BALL MILL DRUM Filed July 11. 1966 Sheet of 2 INVENTORS JOHN S. ECKERT a FRANK D. MOORE ATTORNEY United States Patent US. Cl. 241-180 6 Claims ABSTRACT OF THE DISCLOSURE A ball mill drum having improved end closures comprising an outer member having a dish-shaped portion merged with a circumferential, drum-engaging portion; a coplanar inner member secured at its periphery to the outer member, along the line of merger of the dish-shaped and circumferential portions thereof, and a shaft extending through and secured to both the inner and outer members.

The invention relates to a new construction for the head of a ball mill drum. It includes the method of assembling the new ball-mill head.

Some time ago it was customary to form the heads of ball mill drums from cast iron. Since then, baffles and shroud plates have been used to develop sufficient inertia in the heads of the drums to provide deflection on the inside surfaces of the drum heads at least as low as that in the cast heads formerly used.

The drum of the present invention is made of a flat piece and a dished piece with chamfered edge, preferably with stiffening plates, the dished piece terminating at its circumference in a cylindrical portion. For large heads reinforcing tubes join the two pieces at positions intermediate their center and circumferences. The new head may include a new bafiie design located between the two pieces of a head for circulating a liquid through the head to and from a jacket on the body of a drum.

The construction has been designed so that the heads are readily assembled over a shaft which is located centrally of the head, by welding the pieces to the shaft and to one another. The construction and method of assembly are simple and are explained in connection with the ac' companying drawings, in which- FIGURE 1 is a side elevation of a ball mill drum with one head partly broken away to show its construction;

FIGURE 2 is an exploded partial view of the head of the drum during its assembly;

FIGURE 3 is an enlarged partial view of the assembled head;

FIGURE 4 is an enlarged partial sectional view embodying reinforcing pipes;

FIGURE 5 is an end view of a drum provided with a cooling jacket;

FIGURE 6 is an enlarged section on the line 66 of FIGURE 5; and

FIGURE 7 is an enlarged sectional detail on the line 7-7 of FIGURE 5 showing the gasket between the baifie and the dished head.

The drum of FIGURE 1 includes the body portion 1, suitable shafts 2 and 3 in the heads and a usual opening and cover 4 giving access to the drum, and shows in detail the head construction. As illustrated in FIGURE 2, the head is assembled from the flat inner piece 6, the smaller fiat stiffening plate 7, the dished outer piece 8 which terminates circumferentially in a cylindrical portion 10 which joins the dished portion to the knuckle radius 11, and the dished stiffening plate 12. In assembling the head the inner flatpiece 6 and stiffening plate 7 are first welded to the shaft 3. As shown, the stiffening plate is preferably first welded to the shaft and then the inner "ice piece 6 is welded to the end of the shaft and the inner piece 6 and stiffening plate 7 are welded together. The dished outer piece 8 is then placed over the shaft and the circumference of the inner plate 6 is made to fit into the knuckle radius 11 where, as shown in FIGURE 3, the two pieces are welded together. The outer piece 8 is then welded to the shaft and then the stiffening plate 12 is welded to the shaft, and outer plate 8 and stiffening plate 12 are welded together. This makes a very rigid construction.

Reinforcement may be desired such as shown in FIG- URE 4, especially for larger drums about five feet or more in diameter. For this purpose circular openings are provided in the outer member 8 at a position intermediate the knuckle radius 11 and the shaft. There are usually three or four or more such openings which generally, but not necessarily, are the same size and usually these will be located the same distance from the shaft and will be spaced about the same distance from one another. A short length of metal tube 23 is inserted in each of these openings and seated against the inner piece 6 or the stiffening plate 7 if it is sufficiently large. The tube is internally welded to this plate 6 and then externally welded to the piece 8.

FIGURE 6 illustrates a modification of the structure to be used with a drum having a cooling or heating jacket, the shell of the jacket being welded to the ring 31 which, in turn, is welded to the cylindrical portion 32 of the outer piece 33. The shaft 35 is constructed with channels 37 and 38 for two-way flow of a liquid into and out of the space in the head, through openings 40 and 41 in the shaft. The liquid passes through an opening 43 into the passage 44 and thence through opening 45 in the ring 32, into the jacket of the drum. The used cooling liquid returns by a similar passage to the other half of the head 33. The head is partitioned internally to keep these liquids separate. This is done by welding a partition (FIGURES 5 and 7) to the inner piece 51 (FIGURE 6). The elastic seal 55 (FIGURE 7) is adhered to the outer piece 33 by any suitable adhesive or other means but usually by compression alone. This seal 55 is grooved at 56 along its inner edge, and the outer edge of the partition 50 fits snugly into this groove. The elastomeric seal 55 maintains a liquid-tight division of the head in spite of expansion and contraction of the various elements of the head.

This invention is covered in the claims which follow.

We claim:

1. A ball mill drum having opposed end closure means, each comprising an outer member having a dish-shaped portion merged with a circumferential, drum-engaging portion; a planar inner member having an interior surface defining an end wall of said drum, said inner member being secured at its periphery to said outer member, along the line of merger of said dish-shaped and circumferential portions thereof; coaxially aligned apertures in said inner and outer members; and shaft means positioned in said apertures and secured to said inner and outer members.

2. The ball mill drum as defined in claim 1 further comprising reinforcing means in the form of plates secured in face-to-face relationship with said inner and outer members, in the vicinity of said apertures.

3. The ball mill drum as defined in claim 2 wherein said reinforcing means further comprises at least one additional aperture in the dish-shaped portion of said outer member, and structural means extending through said last mentioned aperture and into engagement with said inner member, said structural means being secured to both said inner and outer members.

4. The ball mill drum as defined in claim 1 further including at least one additional aperture in the dish-shaped portion of said outer member, and structural means extending through said last mentioned aperture and into engagement with said inner member, said structural means being secured to both said inner and outer members.

5. The ball mill drum as defined in claim 1 further including jacketing means surrounding said drum and having lateral termini at least one of which is in sealing engagement with said dish-shaped portion of one of said opposed outer members; spaced openings in the dishshaped portion of one of said outer members, communicating With the interior of correspondingly spaced portions of said jacketing means; bafile means blocking direct communication between said spaced openings, separate passageways in said shaft means each communicating with one side of said batfie, thereby providing a continuous path for uni-directional fluid flow through said jacketing means.

6. The ball mill drum as defined in claim 5 wherein said bafile means includes a resilient element operative to maintain the structural integrity of said baflle means during expansion and contraction caused by environmental changes.

References Cited UNITED STATES PATENTS 1,211,111 1/1917 Dunn. 1,005,933 10/1911 Brown 220-68 XR 1,757,923 5/ 1930 Russell 220-71 2,334,334 11/ 1943 Lapshamsky 220-68 2,374,745 5/ 1945 Grimm. 2,765,098 10/1956 Tangard 220-68 119,465 10/1871 Keen 259-89 3,132,846 5/1964 Siddall 259-90 X ROBERT C. RIORDON, Primary Examiner.

I. F. MCKEOWN, Assistant Examiner.

US Cl. X.R. 

